1. Field of the Invention
The invention relates to an electric axle drive for a motor vehicle, having an electric machine for driving at least one output shaft of the axle of the motor vehicle, and having a spur gear unit.
2. Description of the Related Art
WO 2011/076542 A1 discloses an electric axle drive that has an electric machine with an output shaft that runs parallel to the axle of the motor vehicle. A gear stage applies the torque of the electric machine to a differential, arranged on the axle. The gear stage is a single-stage spur gear unit connected upstream. The electric axle further has a torque-vectoring unit that acts on a layshaft gear unit so that the torques can be distributed within the axle on a wheel-specific basis. The layshaft gear unit is composed of two power-split planetary gear units that have the same dimensions and are shifted in parallel. The wheel-specific distribution of the torques can be adjusted in an infinitely variable fashion by the torque of an electric machine of the torque-vectoring unit. A load-compensating gear stage, as an active stage in the form of a planetary gear unit, is connected downstream of the power-split planetary gear units to combine the torque flux, split by the power-splitting planetary gear units, for the output.
An object of the invention is to provide an electric axle drive for a motor vehicle that enables a vehicle to be driven purely electrically over a wide speed range, with optimum efficiency of the axle drive.